Do not blend opaque windows.

Romain Guy · pixelflinger · commit 7036fdd099fe · 2011-09-26T16:12:04.000-07:00
This change ensures the wallpaper is rendered into an opaque surface
which avoids a glClear() in SurfaceFlinger. This should save quite
a bit of work on every frame when panning the workspace in launcher.

Change-Id: Id43d3498a54c2d60ec4ee3377c92ef79bff55bc1
diff --git a/services/java/com/android/server/wm/WindowState.java b/services/java/com/android/server/wm/WindowState.java
@@ -636,7 +636,7 @@ Surface createSurfaceLocked() {
                 final boolean isHwAccelerated = (mAttrs.flags &
                         WindowManager.LayoutParams.FLAG_HARDWARE_ACCELERATED) != 0;
                 final int format = isHwAccelerated ? PixelFormat.TRANSLUCENT : mAttrs.format;
-                if (isHwAccelerated && mAttrs.format == PixelFormat.OPAQUE) {
+                if (!PixelFormat.formatHasAlpha(mAttrs.format)) {
                     flags |= Surface.OPAQUE;
                 }
                 mSurface = new Surface(

Original file line number	Diff line number	Diff line change
`@@ -636,7 +636,7 @@ Surface createSurfaceLocked() {`
`636`	`636`	`final boolean isHwAccelerated = (mAttrs.flags &`
`637`	`637`	`WindowManager.LayoutParams.FLAG_HARDWARE_ACCELERATED) != 0;`
`638`	`638`	`final int format = isHwAccelerated ? PixelFormat.TRANSLUCENT : mAttrs.format;`
`639`		`- if (isHwAccelerated && mAttrs.format == PixelFormat.OPAQUE) {`
	`639`	`+ if (!PixelFormat.formatHasAlpha(mAttrs.format)) {`
`640`	`640`	`flags \|= Surface.OPAQUE;`
`641`	`641`	`}`
`642`	`642`	`mSurface = new Surface(`